| Main Title |
Support: Determination of Aromatase Activity in Ovary and Liver Tissue of a Reproductive Study in Rats with Chloronicotinyl with TSCA Health and Safety Study Cover Sheet dated 09/24/1998. |
| CORP Author |
Bayer A.G., Wuppertal (Germany, F.R.).; Environmental Protection Agency, Washington, DC. Office of Toxic Substances. |
| Year Published |
1998 |
| Report Number |
8EHQ-1098-13543 |
| Stock Number |
OTS0558417-3 |
| Additional Subjects |
Toxicology ;
Health effects ;
Toxic substances ;
Chloronicotinyl ;
Reproduction ;
Fertility effects ;
Teratogenicity ;
Mammals ;
Rats ;
Oral ;
Diet ;
Biochemistry ;
CAS No 111988-49-9
|
| Holdings |
| Library |
Call Number |
Additional Info |
Location |
Last
Modified |
Checkout
Status |
| NTIS |
OTS0558417-3 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
| Collation |
397p |
| Abstract |
YRC 2894 is a new chloronicotinyl insecticide which is under development as an insecticide against sucking insects. Both an increase in stillbirths as well as signs of dystocia (difficult labor) were noted during the 1st generation of a 2-generation reproductive bioassay with YRC 2894. To develop data that could contribute to a mechanistic understanding of the YRC 2894-induced alterations in the two reproductive endpoints, a modified 1-generation reproductive study was designed, which included a pre-mating phase, a gestation phase, and a post-partum phase. Exposure was carried out via the diet at constant concentrations of either 0 or 800 ppm YRC 2894. (See W.R. Christenson, Study No.96-972-KF, BAYER Report No. 108360; TX8604). Significant elevations in circulating estradiol, and to some extent also of progesterone, corticosterone, and luteinizing hormone were measured, however, estrogen and progesterone receptor populations in the cytosolic and nuclear fractions of the uterus remained unchanged. The increased plasma concentration of estradiol could be the result of an induced aromatase activity. The aromatase (cytochrome P450 XIX, CYP 19) is necessary for the biosynthesis of estrogen in several tissues. Since YRO 2894 induces specific cytochrome P450 enzymes, YRC 2894 may also induce aromatase (cytochrome P450 19). This hypothesis was investigated in the present study. Aromatase activity was measured by the tritiated water assay in ovary and liver tissue. The results of this study suggest that the increased plasma concentration of estradiol, produced by YRC 2894 in rats (SD), is at least partly due to an effect on the liver to increase synthesis of estradiol through a significant induction (1.9 fold) of aromatase cytochrome P450 in the endoplasmic reticulum. A direct effect on the aromatase in the ovary was not obvious. |
| Supplementary Notes |
The quality of the documents listed in the Office of Toxic Substances database may not meet usual NTIS standards but are included to further the opportunity for the scientific and technical community to locate materials which may not be available elsewhere. The content is the responsibility of OTS. Sponsored by Environmental Protection Agency, Washington, DC. Office of Toxic Substances. |
| Availability Notes |
Product reproduced from digital image. Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA. |
| PUB Date Free Form |
10 Sep 1998 |
| Category Codes |
57Y; 57U; 68G; 99; 44G |
| NTIS Prices |
PC A18/MF A18 |
| Document Type |
NT |
| Cataloging Source |
NTIS/MT |
| Control Number |
010500020 |
| Origin |
NTIS |
| Type |
CAT |
